--TEST-- DateTimeZone::getOffset() accepts a DateTimeInterface object --FILE-- <?php $tz = new DateTimeZone('Europe/London'); $dt = new DateTimeImmutable('2014-09-20', $tz); echo $tz->getOffset($dt); echo $tz->getOffset(1); --EXPECTF-- 3600 Warning: DateTimeZone::getOffset() expects parameter 1 to be DateTimeInterface, integer given in %s